Thread controlling and defect detecting device



Sept. 19, 1950 E. DOLL 2,522,751

THREAD CONTROLLING AND DEFECT DETECTING DEVICE Filed Dec. 1, 1947 2Sheets-Sheet 1 g? ML:

/mm flygg 1 2 Sheets-Sheet 2 fiMM MKr/M E DOLL THREAD CONTROLLING ANDDEFECT DETECTING DEVICE x JP Sept. 19, 1950 Filed Dec.

Patented Sept. 19, 1950 UNITED STATES PATENT OFFICE THREAD CONTROLLINGAND DEFECT DETECTING DEVICE Edouard Doll, Paris, France ApplicationDecember 1, 1947, Serial No. 789,094 In FrancetSeptember 22, 1947 18Claims.

The present invention .has for its object to 'provide a device forcontrollingand detecting defects in threadscoming out of spinning andtwisting frames with a view to removing the defects which appear on saidthreads and are likely to be prejudicial to their appearance, and totheir mechanical properties, ,whileavoiding useless stoppings ofsaidrthreads.

The devices which aregenerally used for this purpose often comprise aslot with two fixed edges through which passes the thread ,to becontrolled, the plane of said edge being perpendicular oreven oblique tothe direction of circulation of .lthethrtead. The .width of said slot isadjusted in such a. manner that defects exceeding a certain diameter butwhatever their length, cannot pass therethrough, the thread being thusstopped and eventually broken if it is stretched further.

In certain cases, in order to insurea greater sensitivity, the stoppingr device is formed of y a movable slotted plate which is shifted by thefriction of the defect and throughanyrnechanical meansreleases, theclosure of a second member which thenwclamps the thread energeticallyand insures the certain breaking thereof.

The control principles and the operation of both devices are technicallyidentical; they step all the defects having a sufficient diameter forbeing clamped inthe slot irrespective of the length of the defect.

Other arrangements which, aremore complicated are provided withsuccessive b ades in order that a defect having, escaped ,oneof them isstopped by an exactly similar blade located behind the first one butalways irrespective of the length of the defect.

Furthermore, other arrangements provide means for avoiding the breakingwhen a knot :passes but without giving the possibility of anydiscrimination between a well made knot well i made warpers knot) and avery thick knot (a badly made warpers knot or, anordinaryknot) or even alarge knot having a very distinct rounded form as it, is often the case.Now, the

passage of both these latter defects withoutany breaking isprejudicialto the appearance, and

to the mechanicalproperties ofthe threads, The devices, of this kind,are, provided with movable mechanical members which shift toaallo wvthepassage of warpers knots and suchdefects which are presumed to beacceptable, which renders often thefinest ones tend to be fiattened andto pass through the control slots without causing the breaking of thethread. It is thusneeessary to provide a ,very narrow slot which must-beadjusted with precision, but then the thread drawn constantly through anarrow slot breaks on the smallest knot, even if almost imperceptible,and more particularlyit isunravelled on its whole length which islargely prejudicial to its appearance and its mechanical properties.Furthermore, the ,precision of adjustment re- -quired in order that adevice may be eflicient irrespective of its degree of improvementrequires, in all the existing devices, the constitution of records afterexperiments made on numerous thread diameters and the use of gauges; theadjustment of a device on starting 'withone quality of thread is a longoperation which must be repeated on a very largenumber of devices usedsimultaneously the production of each device being very small.

The device according to the present invention 'makes it possible-toavoid all the above nentioned disadvantages vizQ:

Unnecessary stops for insignificant defects,

Passage of badly made or very large knots,

Impossibility of use for high linear speeds owing to the inertia ofthedinovable selecting mem- 'bers,

-Flattening of long defects, Unravelling of the thread,

Material difliculty of adjusting each device and to deter-mine thebestsuitable adjustment, Impossibility of ascertaining the getting outoforder of a device'for any reason through a simple observation,

Clogging of the cleaners,

said devices unusable on modern great speed winding-machines because theinertia of such movable members would cause the breaking of the threadbefore the shifting could have oceach of said disadvantages beingsufiicient when taken separately for making a device ineffective orpractically unusable.

The device according to the invention comprises two thread guides of aknown type determining the axis of circulation oi the thread and betweensaid thread guides in the direction of circulation of the thread,successively, a selecting blade arranged obliquely with respect to theaxis oi circulation or the thread and provided, in a horizontal planecontaining said axis, with a slot the opening of which is slightlylarger than the diameter oi the thread and through which the threadcirculates, a first stopping member provided, perpendicularly to theaxis of circulation, with a slot-shaped passage located in the plane ofthe slot in the oblique blade said member extending between the frontend of the oblique blade and a point in the neighbourhood of the axis ofcirculation of the thread without reaching the latter, the threadcirculating normally outside said member and the opening of said passagebeing substantially equal to the diameter of the thread, and, after thisfirst stopping member, a second stopping member comprising a slotperpendicular to the axis of circulation of the thread and offering tothe latter a passage equal to the diameter o'l a well made knot, thethread always circulating through said member.

Two embodiments of the device according to the invention are describedhereafter with reference to the appended drawings, in which:

Figure l is a diagrammatical plan view of a simple type of said device.

Fig. 2 is a sectional view through line iii-11 of Fig. 1.

Fig. 3 is an elevational view showing a practical embodiment of a devicewith adjustment of the width of the slots.

Fig. 4 is a plan view corresponding to Fig. 3.

Fig. 5 is a detail view showing the adjustment means or" the slope ofthe base plate or" the device of Fig. 3. v

Fig. 6 is a detail view showing the levers for controlling theadjustment of the progressive opening of the oblique plate and of thesecond stopping member in the device of Fig. 3.

The device shown in Figs. 1 and 2 comprises a base plate I, two pig tailthread guides 22 between which the thread 3 circulates from A towards Band between said thread guides, successively, a blade l oblique withrespect to the axis of circulation of the thread and provided in thehorizontal plane containing a slot 5 at said axis the width of whichincreases in the downstream direction, or the direction of travel of thethread, from the entrance point 5a where it is slightly larger than thediameter of the thread, till the exit point 5b where it is scarcelysmaller than the diameter of an acceptable knot. A blade 5 isperpendicular to the downstream direction AB, provided in the horizontalplane of circulation or" the thread with a slot '1 the width of which isscarcely larger than the diameter of thread 3, said blade 6 extendingbetween the end 51) of the slotted blade 3 and a point 5b near the axisAB without reaching the latter and, lastly, f

a slotted blade 8 perpendicular to the axis AB, the slot 9 of this bladethe width of which is slightly larger than the diameter of a well madeknot being located in the horizontal plane of circulation of the thread.An abutment l0 limits the displacement of the thread on the side opposedto plate 6.

Any defect appearing before the oblique blade Ll creates a resistanceresulting in a force R which can be resolved into a force R1perpendicular to the plane of the plate and a force R2 acting in 4 thedirection 5a5b. Under the influence of R2 the thread is displacedtowards 51) while forming an angle and this until the point where thewidth of slot corresponds to the passage of the diameter of the defect.Two cases may occur:

(1) The defect has larger diameter than the thread and a smallerdiameter than a warpers knot. The defect passes below the oblique bladeat the point X1 where the width of the slot is equal to the diameter ofsaid defect. At this moment the thread which was displaced laterally hasentered the slot l of blade 6. Two possibilities then arise:

(a) The defect has a length which is smaller than the distance, measuredon the line passing through X1 and the exit \pig tail, which separatespoint X1 from the arc of circle Y2. centered on the entrance pig tailand tangent to blade 6; in this case, after having passed through theoblique slot 5 the thread is freed and returned immediately to itsnormal position before it resumes its forward movement; the defectpasses on the side oi blade 6 and through the device without causing anystopping since it is necessarily thinner than the opening of the nextfollowing blade 8;

(b) The length of the defect is longer than the distance from X1 to thearc of circle YZ; the defeet is clamped in slot 7 of blade 6 and thethread is broken.

The shape of the triangle with a circular side Y, Z shows that thelarger the defects, the smaller the minimum distance on which they arestopped; all the defects which find their way through slot 5 betweenpoint Z and the end 51) are stopped, even if they have the shape of asimple point.

(2) The defect has a diameter equal to or larger than that of a warpersknot; it then slides on the whole length of the oblique blade 55,shifting the thread in the slots 5 and 6 till it leaves at their otherend 519. As soon as the defect escapes at the end of the oblique blade4, after having passed blade 6 which could not act upon the defect owingto the protection afforded by the oblique blade 4 the thread is freed asin the first case and tends to resume its place by passing through theslots again but in the reverse direction, the defect describing an arcof circle centered on the entrance pig tail and passing through thedownside end 52) of the oblique blade 4. When moving further, the defectengages blade 8. Two possibilities may again arise:

(a) If the defect is a well made warpers knot it passes through slot 9adjusted for this [purpose.

(b) If the diameter of the defect is larger than that of a warpers knot,e. g. a large plug or a badly made knot, it is arrested by blade 8 andthe thread is broken if it is stretched further.

The abutment it limits the displacement of the returning thread in orderto avoid that the thread carried along through the rapidity of thismovement and the weight of a thick defect leaves on the other side ofthe device, thus being likely to pass beside the slot 9.

Experience shows that for obtaining a good result the ratios of theopenings of the three slots 5 (at point X) l and 9 must beapproximatively the following, irrespective of the thickness of thethread:

Opening l:(opening 5 at point X) 0.9 7 Opening tzl'opening 5 at point X)l.6 Opening 5 at point 2: (opening 5 at point X) X 1.4

' In the deviceshown in Figs. 3 and 4 the axis of circulation of thethread is again defined by the thread guides 2. The thread circulates ona plate ll the plane of which contains the axis of circulation of thethread, said plate being itself secured on a base plate 12 carrying thethread guides 2 by means of a device which will be hereafter described.-Co-operating with said plate H in order to create slot-shaped openingsequivalent to those above described are an blique blade 13 and a blade14 carried by one of the arms of a bell crank lever l pivotally mountedat It and the other arm of which carries a step 6-? which retains,through a finger 18, the stopping flap 1'9 urged towards the base plate1 I by a return spring 20. The slot-correspending to 9 is created by ablade 21 the lower edge of which leaves between it and the base plate iian interval which is very slightly larger than the diameter-of a warpersknot.

The Widths of the so created slots must be adjusted proportionallyaccording to the diameter of the thread to be controlled. Thisadjustment is effected by actuating a single member forming part of adevice which will be described hereafter with reference to Figs. 3 and 4as well as to Figs. 5 and 6 which are detail views of the same.

The base plate H is urged downwards by a spring 22 and rests, on the onehand, upon the head of a two-pitch screw 23 the other end of whichcomprises a square onto which a set wrench can be applied; the pitch ofthe upper part of screw 23 is double of thatof the lower part. The finepitch :of said screw is screwed into the frame I2 and mounted on thesecond thread is a. nut 24 below which a lever 25 comes to rest which ispivotally mounted around a knife 26, the plate I! resting, on the otherhand, upon the other end of said lever 25.

If the two-pitch screw is turned in one direction or in the other bymeans of the set wrench, the part of the plate ll which rests upon thehead of the screw 23 is shifted according to the movements of said head.

The not 24 which comprises a forked part b "preventing its rotation isshifted along the screw on twice the distance in a direction opposite tothat of plate I I owing to the double pitch of the This results in thatwhen plate H is raised (lowered) at this end by a certain amount the nutis, on the contrary, lowered (raised) by the same amount and transmitsthis movement to lever 25. Said lever, while rocking "around knife 25,imparts to the other end of the plate a. movement in the same directionas that imparted to the part resting on the screw and which is equal worproportional to that of the head of the two-pitch screw, according asthe position of knife 26 is chosen at the centre or off-set towards oneof the ends of lever 25. Thus, for obtaining below blade !4 an openingequal to 0.9 of the opening below bladel3 atpoint X said knife isslightly off-set towards that end oflever 25 upon which the plate I lrests "directly. Once determined said position of knife it remains validirrespective of the thickness of the thread.

It remains to determine the automatic adjust- "ment of the opening inblade $21 and of the progressive opening (which is not indispensable butinsures a more regular working) from X to Z of theoblique blade 93, asshown in Fig. 6.

Both said bladeslare secured to a single support 21 pivotally mountedaround an axis 28 slot 4.

30 rocking around shaft 3! acts upon finger 29- of support El of bladesl3 and 2| while raising it; the slot opened below plate 2| bythelowering of plate H is thus amplified by the raising of said blade 2!fast with support 21. The rocking points of the support and the rockinglever are calculated in order to obtain a total opening at this point ofabout 1.6 times the opening obtained at point X (this opening of 1.6 Xcorresponds to the passage of a warpers knot the diameter of which isalways substantially proportional to that of the thread).

In order that this proportionality may be observed it is necessar thatwhen the plate is raised until it engages blade l4 both other blades l3and 2! must also be engaged. This is the initial mounting adjustment.

The progressive opening from X .to Z; of blade I3 is obtainedsimultaneously since said blade is fast with blade 2!. If it is desired,for example, to obtain at Z an opening equal to 1.4 times the opening atX, it is sufiicient, the opening below blade 2| being equal to 1.6 timesthe openingat X, that point Z is at 7 of the distance from point X andfromblade 2|.

Support 27 comprises, furthermore, a finger -33 projecting outside theframe adapted for making it possible for the operator to raise it inorder to free a defect caught in the device. By raising support 21 bothblades l3 and 2! secured to said support are raised and, furthermore,blade 2| acting through its upper edge upon the twoarmed lever l5 causesblade M to rock and opens During this operation the operator retains thearresting flap it through its engaging finger in order that it does notcome to clamp the thread. It is upon said finger 34 that the operatoracts in order to return it to its position when it drops down upon thethread owing to the working of the stopping device. When finger 33 is nolonger acted upon all the blades automatically return to their correctposition under the influence of spring 32; thus the thread which hasbeen knotted again may be controlled further.

Th adjustment of the device is elfected without any gauge and without itbeing necessary to know the exact characteristics of the thread. To thisend, the adjustment is proceeded with as follows:

Before the thread is set in motion, the screw 23 is first adjusted toopen the slots to an extent beyond that required for the subsequentoperation of the device, and if desired, to their maximum openpositions.

The thread is then set in motion and the device is closed by means ofthe adjustment wrench until it is observed that owing to the clamping atX below blade I3 the thread carried along by its movement is off-set inthe direction of Z.

Thedevice is then slightly loosened for causing the thread to circulatebelow blade 13 again in the neighbourhood of point X while maintainingit in a certain vibration due to the rubbing against blade l3. Thisvibration which is easily perceptible in the course of an inspection isthe proof that the device is not too widely open, which would render itineiiective; the permanent oil-setting of the thread in the direction ofZ indicates, on the contrary, a too strong clamping which would causebreakings for the smallest defect, the thread being then, contrary tothe principle of the present device, constantly engaged below blade Hi.

In both the specification and claims, the use of the term upstream endand downstream end is intended to mean respectively, the ends from whichand toward which the thread is travelling.

What I claim is:

1. A device for controlling and detecting defects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread and, between said thread guides, in thedirection of the circulation of the thread, successively, a selectingblade arranged obliquely with respect to th axis of circulation of thethread and provided, in a horizontal plane containing said axis, with aslot the opening of which is slightly larger than the diameter of thethread, a first stopping member provided, perpendicularly to the axis ofcirculation, with a slot-shaped passage located in the plane of the slotin the oblique blade between the downstream end of said blade and apoint in the neighbourhood of said axis without reaching the latter, theopening of said passage being substantially equal to the diameter of thethread and, on the downstream side of this latter unit, a secondstopping member perpendicular to the axis of circulation of the threadand offering to the latter a passage equal to the diameter of a wellmade knot on the thread.

2. A device for controlling and detecting defects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread and, between said thread guides, in thedirection of the circulation of the thread, successively, a selectingblade arranged obliquely with respect to the axis of circulation of thethread and provided, in a horizontal plane containing said axis, with aslot the opening of which widens out from the en- I trance end to theexit end, said slot having at its most closed point an opening equal tothe diameter of the thread and at its most opened point an opening whichis slightly smaller than the diameter of a warpers knot made on thethread, a first stopping member provided, perpendicularly to the axis ofcirculation of the thread, with a slot-shaped passage located in theplane of the slot in the oblique blade between the downstream end ofsaid oblique blade and a point in the neighbourhood of said axis withoutreaching the latter, the opening of said passage being substantiallyequal to the diameter of the thread and, finally, on the downstream sideof this unit, a second stopping member perpendicular to the axis ofcirculation of the thread and offering to the latter a passage equal tothe diameter of a well made knot on the thread.

3. A device for controlling and detecting defects in textile threads,which comprises two thread guides of known type determining the axis ofcirculation of the thread and, between said thread guides, in thedirection of the circulation of the thread, successively: a selectingblade arranged obliquely with respect to the axis of circulation of thethread and provided, in a horizontal plane containing said axis, with aslot the opening of which widens out from the entrance end to the exitend, said slot having at its most closed point an opening equal to thediameter of the thread and at its most opened point an opening which isslightly smaller than the diameter or a warpers knot made on the thread,a first stopping member constituted by a cleaning device provided with aslot formed of a blade perpendicular to the axis of circulation of thethread and in which a slot is provided which is open at both its endsand the width of which is substantially equal to the diameter of thethread, said slot being located in the plane of circulation of thethread between the downstream end of the slot in the oblique blade and apoint in the neighbourhood of said axis of circulation without reachingthe latter and, finally, on the downstream side of this unit, a secondstopping member constituted by a defect detecting device provided with aslot formed of a blade perpendicular to the axis of circulation of thethread and in which a slot is provided which is open at both its ends,and the width of which is substantially equal to the diameter of a wellmade knot on the thread.

4. A device for controlling and detecting de facts in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread may slide longitudinally and laterally,and three blades arranged above said base plate substantiallyperpendicularly to the plane of the latter and each providing againstsaid base plate a passage slot for the thread, the first blade beingarranged obliquely with respect to the axis of circulation of the threadand providing a passage slot the width of which is slightly larger thanthe diameter of the thread, the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between thedownstream end or the oblique blade and a point in the neighbourhood ofsaid axi without reaching the latter, and providing a passage slot thewidth of which is substantially equal to the diameter of the thread, andthe third blade, substantially parallel to the second blade, providing apassage slot the width of which is substantially equal to the diameterof a well made knot on the thread.

5. A device for controlling and detecting defects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread may slide longitudinally and laterally,means being provided to shift said plate perpendicularly to its plane,and three blades arranged above said base plate substantiallyperpendicularly to the plane of the latter and each providing againstsaid base plate passage slot for the thread, the first blade beingarranged obliquely with respect to the axis of circulation of the threadand providing a passage slot the width of which is slightly larger thanthe diameter of the thread, the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between thedownstream end of the oblique blade and a point in the neighbourhood ofsaid axis without reaching the latter, and providing a passage slot thewidth of which is substantially equal to the diameter of the thread, andthe third blade, substantially parallel to the second'bladaproviding a:passage slotthe width of which is substantially equal to the diameter ofawellrmadeknot on the thread.

6. A deviceforcontrolling and detecting defects in textile threads whichcomprises two thread guides of known type determining the axisofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread may slide longitudinally and laterally,and three blades arranged above said base plate substantiallyperpendicularly to the plane of the latter and each providing againstsaid base plate a passage slot for the thread, the first blade'beingarranged obliquely with respect to the axis of circulation of the threadand providinga passage slot the width of which is slightly larger thanthe diameter of the thread, the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between thedownstream endof the oblique blade and a point in the neighbourhood ofsaid axis without reaching the latter, and providing a passage slot thewidth of which is substantially equal to the diameter of the thread,said blade being carried by one of the arms of a two-arm lever pivotallymounted on a shaft parallel with the direction of the blade and theother arm of which is provided with a step arranged to maintain, againstthe action of a return spring which tends to press it downontothepolished plate, a flap pivotally mounted on a shaft parallelwith thearticulation shaft of the two-arm lever, and the third blade,substantiallyparallel to the second blade, providing a passage slot thewidth of which is substantially equal to the diameter of a well madeknot on the thread.

7. A device for controlling and detecting defects in textile threadswhich comprises two threadguides'of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which thethread may slide longitudinally and laterally,means being providedto'shift said plate perpendicularly to its plane,andthree blades arranged above said base plate substantiallyperpendicularly to theplane of the latter and each providing againstsaid *base plate a passage slot for the thread, the first blade beingarranged obliquely with respect to the axis of circulation of the threadand providing a passage slot the widthof which isslightlylarger than thediameter of the thread; the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between thedownstream end of the oblique blade and a point in the neighbourhood ofsaid axis without reaching the latter, and providing a passage slot thewidth of which is substantially equal to the diameter of the thread,said blade being carried by one of the arms of a two-arm leverpi'votallymounted on a shaft parallel with the direction of the blade and theother arm of which is provided with a step arranged to maintain, againstthe action of a return spring which tends to press it down onto thepolished plate, a flap pivotally mounted on a shaft parallel with thearticulation shaft of the two-arm lever,. and the-third blade,substantially parallel to thesecond blade, providing a passage slot thewidth of which is substantially equal to the di-- ameter. of a well madeknot on the thread;

8. A' device for controlling anddetecting defects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the threadmay slide longitudinally and laterally,and three blades arranged above said base plate substantiallyperpendicularly to the plane of the latter and each providing againstsaid base plate a passage slot for the thread, the first blade be-- ingarranged obliquely with respect to the axis of circulation of the threadand providing a passage slot the width of which increases from the pointof said blade located on the axis of circulation of the thread, where itis very slightly larger than the diameter of the latter, to thedownstream end of said blade, where it reaches approximately one and ahalf times said diameter, the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between saiddownstream end of the oblique blade and a point in the neighbourhood ofsaid axis without reaching the latter, and providing a passageslot thewidth of which is substantially equal to the diameter of the thread, andthe third blade, substantially parallel to the second blade, providing apassageslotthe width of which is substantially equal to the diameter ofa well made knot on the thread.

9. A device for controlling and detecting defects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread may slide longitudinally and laterally,means being provided to shift said plate perpendicularly to its plane,andthree blades arranged above said base plate substantiallyperpendicularly to the plane of the latter and each providing againstsaidbaseplate'a passage slot for the thread, the first blade beingarranged obliquely with respect to the axis of circulation of the threadand providing a passage slot the width of which increases from the pointof said blade located on the axis of circulation of the thread, where itis very slightly larger than the diameter of the latter, to thedownstream end of said blade, where it reaches approximately one. and ahalf times said diameter, the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between saiddownstream end of theoblique blade and a point in the neighbourhood: ofsaid axis without reaching the latter, and providing a passage slot thewidth of which is substantially equal to the diameter of the thread,said blade being carried by one of the arms of a two-arm lever pivotally mounted on a shaft parallel with the direction of the blade and theother arm of which is provided with a step arranged to maintain, againstthe action of a return Spring which tends to press it down onto thepolished plate, a flap pivotally mounted on a shaft parallel with thearticulation shaft of the two-arm lever, and the third blade,substantially parallel to the second blade, providing a passage slot thewidth of which is substantially equal to the diameter of a wellmade knoton the hread.

10. A device for controlling and detectingdefects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread'ma-y, slide longitudinally andlaterally,

said plate, slidably mounted in a general frame and urged downwards by aspring, resting on one hand on the end of a two-pitch screwthe smallerpitch of which is engaged in a tapped hole in the said general'frameand' the larger, whichlis double of the smaller, is engaged in a nutand, on the other hand, on the end of a lever which rests on a knife andthe other end of which is engaged under said nut, and three bladesarranged above said base plate substantially perpendicularly to theplane of the latter and each providing against said base plate a passageslot for the thread, the first blade being arranged obliquely withrespect to the axis of circulation of the thread and providing a passageslot the width of which increases from the point of said blade locatedOn the axis of circulation of the thread, where it is very slightlylarger than the diameter of the latter, to the downstream end of saidblade, where it reaches approximately one and a half times saiddiameter, the second blade extending substantially perpendicularly tothe axis of circulation of the thread between said downstream end of theoblique blade and a point in the neighbourhood of said axis withoutreaching the latter, and providing a passage slot the width of which issubstantially equal to the diameter of the thread, said blade beingcarried by one of the arms of a two-arm lever pivotally mounted on ashaft parallel with the direction of the blade and the other arm ofwhich is provided with a step arranged to maintain, against the actionof a returnspring which tends to press it down onto the polished plate,a flap pivotally mounted on a shaft parallel with the articulation shaftof the two-arm lever, and the third blade, substantially parallel to thesecond blade, providing a passage slot the width of which issubstantially equal to the diameter of a well made knot n the thread.

11. A device for controlling and detecting defects in textile threadswhich comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread may slide longitudinally and laterally,said plate, slidably mounted in a general frame and urged downwards by aspring, resting on one hand on the end of a two-pitch screw the smallerpitch of which is engaged in a tapped hole in the said general frame andthe larger, which is double of the smaller, is engaged in a nut and, onthe other hand, on the end of a lever which rests on a knife and theother end of which is engaged under said nut, and three blades arrangedabove said base plate substantially perpendicularly to the plane of thelatter and each providing against said base plate a passage slot for thethread, the first blade being arranged obliquely with respect to theaxis of circulation of the thread and providing a passage slot the widthof which increases from the point of said blade located on the axis ofcirculation of the thread, where it is very slightly larger than thediameter of the latter, to the downstream end of said blade, where itreaches approximately one and a half times said diameter, the secondblade extending substantially perpendicularly to the axis of circulationof the thread between said downstream end of the oblique blade and apoint in the neighbourhood of said axis without reaching the latter, andproviding a passage slot the width of which is substantially equal tothe diameter of the thread, said blade being carried by one of the armsof a two-arm lever pivotally mounted on a shaft parallel with thedirection of the blade and the other arm of which is provided with astep arranged to maintain, against the action of a return spring whichtends to press it down onto the polished plate, a flap pivotally mountedon a shaft parallel with the articulation shaft of the two-arm lever,and the third blade,

substantially parallel to the second blade, pro viding a passage slotthe width of which is substantially equal to the diameter of a well madeknot on the thread, both the first and second above-mentioned bladesbeing secured on a same supporting member pivotally arranged on a shaftparallel to the said second blade and applied by means of a spring onone end of a lever the other end of which rests beneath the movable baseplate.

12. A device for controlling and detecting defects in textile threads,which comprises two thread guides of known type determining the axis ofcirculation of the thread to be acted upon and between which is arrangeda base plate on which the thread may slide longitudinally and laterally,means being provided to shift said plate perpendicularly to its plane,and three blades arranged above said base plate substantiallyperpendicularly to the plane of the latter and each providing againstsaid base plate a passage slot for the thread, the first blade beingarranged obliquely with respect to the axis of circulation of the threadand providing a passage slot the width of which increases from the pointof said blade located on the axis of circulation of the thread, where itis very slightly larger than the diameter of the latter, to thedownstream end of said blade, where it reaches approximately one and ahalf times said diameter, the second blade extending substantiallyperpendicularly to the axis of circulation of the thread between saiddown stream end of the oblique blade and a point in the neighborhood ofsaid axis without reaching the latter, and providing a passage slot thewidth of which is substantially equal to the diameter of the thread, andthe third blade, substantially parallel to the second blade, providing apassage slot the width of which is substantially equal to the diameterof a well made knot on the thread.

13. A slub catcher for yarn comprising in combination a pair ofrelatively fixed guide means for travelling yarn, means for causingdeflection of the path of the yarn in accordance with variations in thediameter thereof, said means being positioned between said guide meansand comprising a structure arranged at an acute angle to the normaldirection of travel of said yarn and having a tapered slit through whichsaid yarn passes said slit increasing in width in the direction of saiddeflection of said yarn, and yarn arresting means cooperating with saiddeflection means.

14. A method of detecting diameter variations in filamentary materialtravelling between two relatively fixed points which comprisescontacting the material intermediate the points by opposed surfacesdiverging in a direction at an acute angle to the direction of travelbetween the fixed points to create a component of force tending todeflect the path of the material transversely with, and proportionatelyto, change in diameter, and detecting transverse deflections of thepath.

15. A method of detecting variations in diameter of travellingfilamentary material which comprises deflecting the path of travel ofthe material in accordance with the diameter of the material by passingthe material through a slit increasing in width in a direction making anacute angle with the direction of travel of the material so that thematerial moves transversely in the slit as its diameter varies and thepath of the material is deflected proportionately to diameter changes,and detecting deflections of the path of the material from a normalpath.

16. A slub catcher for filamentary material comprising in combination apair of relatively fixed guide means for travelling filamentarymaterial, a structure located between said guide means and having spacedsurfaces defining a tapered slit, said structure being so oriented withrespect to said guide means that filamentary material travelling betweenthe guide means passes through the slit at an acute angle, and means forarresting the travel of the material upon a predetermined deflection ofthe travelling material toward the wider end of the tapered slit.

17. A slub catcher for yarn comprising a frame, yarn guide means mountedon said frame for passage of yarn therebetween, a member having anelongated tapered slit therein, said member being mounted on said framebetween said guide means with the slit increasing in width in adirection making an acute angle with the direction of travel of theyarn, and means for arresting the travel of the yarn when the yarn isdeflected a predetermined distance toward the wider end of the slit.

18. The slub catcher according to claim 17 wherein said member comprisestwo parts defining the tapered slit, at least one of said parts beingadjustably mounted on the frame so as to permit of variation in thewidth and taper of the slit, and wherein are comprised means for lockingsaid part in adjusted position.

EDOUARD DOLL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,565,851 Hasbrouck Dec. 15, 192520 2,434,091 Arrington Jan. 6, 1948

